1. Field of the Invention
The invention relates to a liquid applicator for applying a liquid to a portion of a wiring harness. Moreover, the invention relates to a method for applying a liquid to a portion of a wiring harness.
2. Description of the Related Art
Wiring harnesses in an automotive vehicle are branched in a complicated manner. For example, FIG. 5 shows a wiring harness W/H where a single bundle of wires W is split into two branch wire bundles Wa and Wb. A cylindrical main wire assembly tube Wh is mounted over the wire bundle W to form a main wire assembly Wh that has one end in proximity to the branch wire bundles Wa and Wb. Cylindrical branch wire assembly tubes TBa and TBb are put on the branch wire bundles Wa and Wb respectively to form branch wire assemblies Wha and Whb that branch off from the main wire assembly Wh. Ends of the branch wire assembly tubes TBa and TBb are inserted into an end of a cylindrical main wire assembly tube TB by about 20 mm.
The main wire assembly tube TB and the branch wire assembly tubes TBa, TBb often are secured to each other by taping. However, as shown in FIG. 5, an adhesive may be use instead of a tape. The adhesive typically has been applied with a needle-type adhesive injector 51 to inject a liquid adhesive into a clearance between the main wire assembly tube TB and the branch wire assembly tubes TBa, TBb. Waterproofing can be applied simultaneously if the respective tubes TB, Tba and TBb are secured by the adhesive.
However, a needle 51a of the injector 51 may not be inserted properly due to a narrow clearance between the respective tubes TB, TBa, TBb. As a result the adhesive may not be applied properly. Alternatively, a forcibly inserted needle 51a may tear the main wire assembly tube TB. These situations may affect the adequacy of the adhesive connection of the tubes.
In view of the above, an adhesive container 52 with a liquid adhesive is placed upside down, as shown in FIG. 6. A sponge 53 then can be pressed against a mouth of the adhesive container 52 to remove the necessary amount of adhesive. Thereafter, as shown in FIG. 7, the sponge 53 is successively rubbed against one end of each branch wire assembly tube TBa, TBb to apply the adhesive 54. The ends of the branch wire assembly tubes TBa, TBb to which the adhesive 54 has been applied then are inserted into the main wire assembly tube TB. Thus, the tubes can be adhered to each other by thoroughly applying the adhesive. The process illustrated in FIGS. 6 and 7 will not tear the main wire assembly tube TB because the adhesive injector 51 and needle are not used.
The method illustrated in FIGS. 6 and 7 requires considerable manual work, and it is fairly cumbersome to apply the adhesive on the sponge 53 with considerable frequency. Additionally, the operation of rubbing the sponge 53 with the adhesive against the branch wire assembly tubes TBa, TBb easily soils the operator. Thus, applying adhesive in the manner described above is a large burden on the operator.
In view of the above problems, an object of the present invention is to provide a liquid applicator and a method for applying a liquid that allows an easier application of the liquid to a portion of a wiring harness.
The invention is directed to a liquid applicator for applying a liquid, preferably a liquid adhesive, to an outer circumferential surface of a portion of a wiring harness. The liquid applicator comprises a liquid coating member with a concave receiving surface for contact with the portion of the wiring harness that is to be coated with the liquid. The liquid applicator further comprises a stand for pivotally supporting the liquid coating member, a liquid supplying means for supplying the liquid to the receiving surface of the liquid coating member, and a pivoting means for pivoting the liquid coating member circumferentially relative to the portion of the wiring harness to be coated with the liquid. Thus, the liquid can be applied substantially over the entire circumference of the selected portion of the wiring harness by pivoting the liquid coating member.
According to a preferred embodiment, the concave receiving surface is a substantially semi-cylindrical receiving surface.
The liquid applicator preferably is an adhesive applicator for applying a liquid adhesive to an outer circumferential surface of a branch wire assembly tube as a step in a wiring harness assembling process. The process may include: placing a main wire assembly tube on a main wire assembly of a wiring harness; applying adhesive to an end of the branch wire assembly tube with an adhesive applicator; putting the branch wire assembly tube on a branch wire assembly branched off from the main wire assembly of the wiring harness; and inserting the leading adhesive-coated end of the branch wire assembly tube into an end of the main wire assembly tube. The adhesive applicator comprises an adhesive coater with a substantially semi-cylindrical receiving surface that can be fit to one end of the branch wire assembly tube. The adhesive applicator further comprises a stand for pivotally supporting the adhesive coater, an adhesive supplying means for supplying the adhesive to the receiving surface of the adhesive coater, and a pivoting means for pivoting the adhesive coater in the circumferential direction of the branch wire assembly tube. Thus, adhesive can be applied to the branch wire assembly tube over its entire circumference by pivoting the adhesive coater with the pivoting means.
The liquid coating member preferably comprises a foamed material, such as a sponge, in which the adhesive or other such is permeable.
The pivoting means may comprise pins that project at each of the opposite ends of the liquid coater with respect to its longitudinal direction, and a pair of arcuate guide means for guiding the pins to pivot the liquid coater. The guide means preferably comprise arcuate rings that face opposite ends of the liquid coater with respect to its longitudinal direction. Each arcuate ring is frame-shaped to define an arcuate engaging groove therein and the pins are fit slideably in the corresponding engaging grooves.
One end of the branch wire assembly tube is placed on the receiving surface of the adhesive coater that has been set at a suitable height. Thus, a lower portion of the outer circumferential surface of the branch wire assembly tube fits in the receiving surface of the adhesive coater. The liquid adhesive is supplied to the receiving surface by the adhesive supplying means, and the supplied adhesive is applied to the lower portion of the outer circumferential surface of the tube in contact with the receiving surface. Adhesive is applied to the remainder of the tube by using the pivoting means to pivot the adhesive coating member in the circumferential direction of the branch wire assembly tube. Therefore, the receiving surface supplied with the adhesive is rubbed against the outer circumferential surface of the cylindrical branch wire assembly tube. As a result, the adhesive is applied to the branch wire assembly tube over its entire circumference.
Accordingly, the adhesive supplying means quickly supplies the liquid adhesive to the receiving surface on which the branch wire assembly tube is placed, and the adhesive supplied to the receiving surface is applied quickly to the branch wire assembly tube merely by employing the pivoting means to pivot the adhesive coating member. Therefore, the adhesive can be applied efficiently to the one end of the branch wire assembly tube before it is inserted into the main wire assembly tube of the wiring harness.
The liquid applicator preferably further comprises switching means for controlling the supply of liquid from the liquid supplying means. The switching means preferably activates the supply of liquid when the portion of the wiring harness to be coated with the liquid is inserted into the liquid coating member.
The adhesive supplying means preferably automatically supplies the adhesive when the branch wire assembly tube is placed on the receiving surface of the adhesive coating member. With this construction, the adhesive is supplied to the receiving surface of the adhesive coating member without performing any particular adhesive supplying operation, and only by placing the branch wire assembly tube on the receiving surface. The supplied adhesive then quickly permeates the adhesive coating member and naturally spreads through a wide area of the receiving surface. Thus, the adhesive can be applied more smoothly and thoroughly.
The adhesive coating member is substantially semi-cylindrical in a preferred embodiment, and therefore the receiving surface is a curved surface of 180xc2x0. Thus, the adhesive can be applied substantially over the entire circumference of the branch wire assembly tube by pivoting the adhesive coating member by 90xc2x0 to left and right.
The invention also is directed to a method for applying a liquid, such as a liquid adhesive, to an outer circumferential surface of a portion of a wiring harness. The method comprises inserting the portion of the wiring harness to be coated into a concave receiving surface of a liquid coating member that is supported pivotally on a stand. The method proceeds by supplying the liquid to the receiving surface of the liquid coating member, and pivoting the liquid coating member in the circumferential direction of the portion of the wiring harness to be coated with the liquid. As a result, the liquid is applied to the portion of the wiring harness substantially over its entire circumference.
The method may further comprise activating the supply of liquid when the portion of the wiring harness to be coated with the liquid is at least partly inserted into the liquid coating member.
The application step preferably comprises applying a liquid adhesive to an outer circumferential surface of a branch wire assembly tube as part of a wiring harness assembling process. The process may further comprise putting the branch wire assembly tube around the branch wire assembly branched off from a main wire assembly of a wiring harness, inserting the leading end of the branch wire assembly tube into an end of the main wire assembly tube put on or around the main wire assembly, and then securing the branch wire assembly tube and a main wire assembly tube by the adhesive.
These and other objects, features and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings.